﻿/*
  KeePass Password Safe - The Open-Source Password Manager
  Copyright (C) 2003-2020 Dominik Reichl <dominik.reichl@t-online.de>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;

using KeePassLib.Utility;

namespace KeePassLib.Cryptography.KeyDerivation
{
  public static class KdfPool
  {
    private static List<KdfEngine> g_l = new List<KdfEngine>();

    public static IEnumerable<KdfEngine> Engines
    {
      get
      {
        EnsureInitialized();
        return g_l;
      }
    }

    private static void EnsureInitialized()
    {
      if (g_l.Count != 0) return;

      g_l.Add(new AesKdf());
      g_l.Add(new Argon2Kdf(Argon2Type.D));
      g_l.Add(new Argon2Kdf(Argon2Type.ID));
    }

    internal static KdfParameters GetDefaultParameters()
    {
      EnsureInitialized();
      return g_l[0].GetDefaultParameters();
    }

    public static KdfEngine Get(PwUuid pu)
    {
      if (pu == null) { Debug.Assert(false); return null; }

      EnsureInitialized();

      foreach (KdfEngine kdf in g_l)
      {
        if (pu.Equals(kdf.Uuid)) return kdf;
      }

      return null;
    }

    public static KdfEngine Get(string strName)
    {
      if (string.IsNullOrEmpty(strName)) { Debug.Assert(false); return null; }

      EnsureInitialized();

      foreach (KdfEngine kdf in g_l)
      {
        if (strName.Equals(kdf.Name, StrUtil.CaseIgnoreCmp)) return kdf;
      }

      return null;
    }

    public static void Add(KdfEngine kdf)
    {
      if (kdf == null) { Debug.Assert(false); return; }

      EnsureInitialized();

      if (Get(kdf.Uuid) != null) { Debug.Assert(false); return; }
      if (Get(kdf.Name) != null) { Debug.Assert(false); return; }

      g_l.Add(kdf);
    }
  }
}
